1. Field of the Invention
The present invention relates to a communication network control system and a control method therefor. More specifically, the invention relates to a communication network control system and a control method therefor, which generates a control information for all of nodes, through which respective paths consist a communication line, on the basis of an input by an operator and feeding the control information to respective nodes as a control command.
2. Description of the Related Art
One example of the conventional communication network system of the type, to which the present invention is directed, will be discussed with reference to a block diagram of FIG. 5. Upon control for opening to traffic of a communication line X formed through a plurality of cross connection device 1 to 4 (hereinafter simply referred to as node), a cross-connect control information input by an operator through a man-machine interface device 10 is transmitted to respective nodes 1 to 4 as cross-connect commands 100 to 400 via a network control unit 20.
An example of the cross-connect control information for each node in the shown case is illustrated in FIG. 6. In FIG. 6, there is shown a cross-connect control information relating to a node 1. The cross-connect control information contains a communication line name (X), a communication line speed, a connection type (cross-connect; a portion shown by dotted communication line in the node 1 of FIG. 5), a control objective node number (node 1), a sender path name (path A), a sender leading time slot number, a destination path name (path B) and a destination time slot number.
The cross-connect control information of such construction are supplied to a cross-connect control portion 21 of a network control unit 20 generated per nodes in a form shown in FIG. 6 by a cross-connect control information generating portion 11.
The cross-connect control portion 21 stores the cross-connect control information per node in a cross-connect control information management database (DB) 23 and generates commands 100 to 400 for respective nodes 1 to 4 with making reference to a path construction information management database (DB) 22.
It should be noted that the following is the reason why the leading time slot numbers and communication line speeds of the sender and the destination are required as the cross-connect control information relating to the communication line X. For example, when a channel of 64 KHz per one channel is multiplexed into 24 channels to transmit through a communication line of 1.55 MHz, a leading end position of the data can be detected by the leading time slot number and a data width (length) can be detected based on the communication line speed. Therefore, the leading time slot number and the communication line speed are included in the content of the cross-connect control information.
Here, considering the cross-connect control information for each of the nodes, through which the communication line X passes, between mutually opposing nodes, the sender path name, the destination path name, the sender leading time slot number and the destination leading time slot number become the same values with each other.
Accordingly, the amount of control information transmitted and received between the man-machine interface device 10 and the network control unit 20 has approximately double redundancy as a whole for a series of control information up to the opening of traffic of the communication line. Transmission and reception of the control information having double redundancy between the man-machine interface device 10 and the network control unit 20 has been a factor of lowering of processing performance of opening communication line to traffic by cross-connect control.